The invention relates to a welding system comprising a welding controller operable in response to instructions from a controller provided with a PLC (Programmable Logic Controller) and the like via a network.
Conventionally, in a case where a field bus serving as communication means, such as a device net, for outputting control instructions from a controller to a welding controller provided with a PLC and welding related general-purpose peripheral equipment is not used, a welding machine and the general-purpose peripheral equipment are controlled by disposing multiple wirings, namely, by effecting multiple wiring connections between the controller provided with the PLC and the like and the welding controller and the general-purpose peripheral equipment. In such a case, since multiple wiring connections are needed for the control instructions, it is very complex in information or instruction transmission and in the formation of instruction means.
Accordingly, it is considered to use well known field bus serving as communication means for transmitting instructions from a controller provided with a PLC and the like to a welding controller and the general-purpose peripheral equipment (general-purpose I/O equipment) as shown in FIG. 2. That is, a control communication is effected by a field bus 36 between a PLC 32 provided in a robot/welding control board 31 and a welding controller 34 and a general-purpose I/O slave 35 of the general-purpose peripheral equipment via a branch tap 33.
Meanwhile, even if the field bus communication means as exemplified by the conventional well known device net as shown in FIG. 2 and the like has been used, there arise problems that the length of each connection lines becomes long and the branch tap 33 has to be used, thereby requiring separately the installation of the general-purpose I/O slave 35, resulting in non-effective utilization of the devices as a whole because the length between the PLC 32 and the welding controller 34 and also the length between the PLC 32 and the general-purpose I/O slave 35 are respectively spaced apart from one another in a long distance.
The invention has been developed in view of the foregoing problems of the prior art, and it is an object of the invention to provide a welding system comprising a welding controller capable of controlling a welding machine and a general-purpose peripheral equipment upon receipt of instructions from a PLC provided in a controller, thereby shortening the length of each connection line and of effectively utilizing devices as a whole by adding a network function for a general-purpose peripheral equipment to a welding controller.
To achieve the above objects, the welding system of the invention is characterized in comprising a welding controller provided with an I/O interface, a controller provided with a programmable logic controller and connected to the I/O interface of the welding controller through a field bus interface serving as communication means, a welding machine connected to the I/O interface of the welding controller through connection lines serving as a network, and a general-purpose peripheral equipment connected to the I/O interface of the welding controller through connection lines serving as another network, wherein the welding controller controls the welding machine and the general-purpose peripheral equipment upon receipt of instructions from the programmable logic controller through the field bus interface.
The invention is further characterized in that the I/O interface of the welding controller bundles the network of the welding machine and another network of the general-purpose equipment.
The invention is further characterized in that the I/O interface has I/O terminals a part of which is connected to the welding machine and another part of which is connected to an I/O circuit of the general-purpose peripheral equipment.